Mobile communications network, communications device, infrastructure equipment and methods

ABSTRACT

Methods are provided for communicating in a mobile network, the mobile network comprising a plurality of infrastructure equipment, each providing wireless connectivity within at least one cell, and a device configured to communicate wirelessly with at least a first of the infrastructure equipment in control of a first cell. In some embodiments, the method comprises determining, at the device, whether a second cell under control of a second of the infrastructure equipment is connected to a first core network operating in accordance with a first protocol or both of the first core network and a second core network operating in accordance with a second protocol, and transmitting, by the device, an automatic neighbor relation report to the first infrastructure equipment, a report comprising an indication of whether the second cell is connected to the first core network or both of the first core network and the second core network.

BACKGROUND Field of Disclosure

The present disclosure relates to mobile communications networkscomprising infrastructure equipment and communications devices, andspecifically provides methods for which source cells may determine whichcore networks are supported by target cells for handover.

Description of Related Art

The “background” description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent it is described in thisbackground section, as well as aspects of the description which may nototherwise qualify as prior art at the time of filing, are neitherexpressly or impliedly admitted as prior art against the presentinvention.

Third and fourth generation mobile telecommunication systems, such asthose based on the Third Generation Project Partnership (3GPP) definedUniversal Mobile Telecommunications Standard (UMTS) and Long TermEvolution (LTE) architecture are able to support more sophisticatedservices than simple voice and messaging services offered by previousgenerations of mobile telecommunication systems. For example, with theimproved radio interface and enhanced data rates provided by LTEsystems, a user is able to enjoy high data rate applications such asmobile video streaming and mobile video conferencing that wouldpreviously only have been available via a fixed line data connection.The demand to deploy third and fourth generation networks is thereforestrong and the coverage area of these networks, i.e. geographiclocations where access to the networks is possible, is expected toincrease rapidly. However, whilst fourth generation networks can supportcommunications at high data rate and low latencies from devices such assmart phones and tablet computers, it is expected that future wirelesscommunications networks, will be expected to efficiently supportcommunications with a much wider range of devices associated with awider range of data traffic profiles, for example including reducedcomplexity devices, machine type communication devices, high resolutionvideo displays and virtual reality headsets. Some of these differenttypes of devices may be deployed in very large numbers, for example lowcomplexity devices for supporting the “The Internet of Things”, and maytypically be associated with the transmissions of relatively smallamounts of data with relatively high latency tolerance, whereas othertypes of device, for example supporting high-definition video streaming,may be associated with transmissions of relatively large amounts of datawith relatively low latency tolerance.

There is therefore expected to be a desire for future wirelesscommunications networks, which may be referred to as 5G or new radioaccess technology (which may be denoted new RAT or, simply, NR)networks, to support efficiently connectivity for a wide range ofdevices associated with different applications with differentcharacteristic data traffic profiles, resulting in different deviceshaving different operating characteristics and/or requirements.

The introduction of new radio access technology (RAT) systems/networkstherefore gives rise to new opportunities as well as challenges. Onesuch challenge is how initially deploy new RAT systems, particularlywhen LTE systems will still be widespread.

SUMMARY OF THE DISCLOSURE

Embodiments of the present technique can provide methods which relate tocommunicating in a mobile communications network, the mobilecommunications network comprising a plurality of infrastructureequipment, each providing wireless connectivity within at least onecell, and a communications device configured to communicate wirelesslywith at least a first of the infrastructure equipment in control of afirst cell.

In some embodiments, the method comprises determining, at thecommunications device, whether a second cell under control of a secondof the infrastructure equipment is connected to a first core networkoperating in accordance with a first communications protocol or both ofthe first core network and a second core network operating in accordancewith a second communications protocol, the second cell being a neighbourof the first cell, and transmitting, by the communications device, anautomatic neighbour relation report to the first infrastructureequipment, the automatic neighbour relation report comprising anindication of whether the second cell is connected to the first corenetwork or both of the first core network and the second core network.

In some embodiments, the method comprises transmitting, by the firstinfrastructure equipment, a connection setup request message, to asecond of the infrastructure equipment in control of a second cell, theconnection setup request message comprising an indication of whether thefirst cell is connected to a first core network operating in accordancewith a first communications protocol or both of the first core networkand a second core network operating in accordance with a secondcommunications protocol, the second cell being a neighbour of the firstcell.

Embodiments of the present technique, which further relate to mobilecommunications networks, communications devices, infrastructureequipment, methods of operating communications devices, and methods ofoperating infrastructure equipment, may provide ways in which sourcecells may determine whether target cells for handover support connectionto the NR core network.

Respective aspects and features of the present disclosure are defined inthe appended claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary, but are notrestrictive, of the present technology. The described embodiments,together with further advantages, will be best understood by referenceto the following detailed description taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings wherein likereference numerals designate identical or corresponding parts throughoutthe several views, and wherein:

FIG. 1 is a schematic block diagram of a first wireless communicationssystem with architectural components corresponding to that of aconventional LTE-based network;

FIG. 2 is a schematic block diagram of a second wireless communicationssystem with architectural components corresponding to that of an exampleenhanced new radio (NR) or 5G network;

FIG. 3 shows an example of how LTE and NR transmissions may bedifferentiated between using time division multiplexing (TDM);

FIG. 4 shows an example of how LTE and NR transmissions may bedifferentiated between using frequency division multiplexing (FDM);

FIG. 5 shows an example of a multicast-broadcast single-frequencynetwork (MBSFN) subframe used to support a LTE/NR coexistence;

FIG. 6 illustrates an exemplary handover procedure involving two corenetworks;

FIG. 7 illustrates the automatic neighbour relation (ANR) function andits environment;

FIG. 8 shows an example describing the intra-LTE/frequency ANR function;

FIG. 9 shows an example describing the inter-RAT/inter-frequency ANRfunction; and

FIG. 10 is a part schematic representation, part message flow diagram ofcommunications between a communications device and an infrastructureequipment of a mobile communications network in accordance withembodiments of the present technique.

DETAILED DESCRIPTION OF THE EMBODIMENTS LTE Technology (4G)

FIG. 1 provides a schematic diagram illustrating some basicfunctionality of a mobile telecommunications network/system operating inaccordance with LTE principles and which may be adapted to implementembodiments of the disclosure as described further below. Variouselements of FIG. 1 and their respective modes of operation arewell-known and defined in the relevant standards administered by the3GPP (RTM) body, and also described in many books on the subject, forexample, Holma H. and Toskala A [1].

The network 100 includes a plurality of base stations 101 connected to acore network 102. Each base station provides a coverage area 103 (i.e. acell) within which data can be communicated to and from communicationsdevices 104. Data is transmitted from base stations 101 tocommunications devices 104 within their respective coverage areas 103via a radio downlink. Data is transmitted from communications devices104 to the base stations 101 via a radio uplink. The uplink and downlinkcommunications are made using radio resources that are licenced forexclusive use by the operator of the network 100. The core network 102routes data to and from the communications devices 104 via therespective base stations 101 and provides functions such asauthentication, mobility management, charging and so on.

Wireless communications systems such as those arranged in accordancewith the 3GPP defined Long Term Evolution (LTE) architecture use anorthogonal frequency division modulation (OFDM) based interface for theradio downlink (so-called OFDMA) and a single carrier frequency divisionmultiple access scheme (SC-FDMA) on the radio uplink.

New Radio Access Technology (5G)

As mentioned above, the embodiments of the present invention can findapplication with advanced wireless communications systems such as thosereferred to as 5G or New Radio (NR) Access Technology. New Radio AccessTechnology (RAT) has been proposed in [2] to develop a new RAT for thenext generation wireless communication system, i.e. 5G, and in 3GPP aStudy Item (SI) on NR has been agreed [3] in order to study and developthe new RAT. The new RAT is expected to operate in a large range offrequencies, from hundreds of MHz to 100 GHz and it is expected to covera broad range of use cases. The use cases that are considered under thisSI include:

-   -   Enhanced Mobile Broadband (eMBB)    -   Massive Machine Type Communications (mMTC)    -   Ultra Reliable & Low Latency Communications (URLLC)

The aim of 5G is not only mobile connectivity for people, but to provideubiquitous connectivity for any type of device and any type ofapplication that would benefit from being connected. Many requirementsand use-cases are still being discussed, but amongst those are:

-   -   Low latency    -   High data rates    -   Millimetre wave spectrum use    -   High density of network nodes (e.g. small cell and relay nodes)    -   Large system capacity    -   Large numbers of devices (e.g. MTC devices/Internet of Things        devices)    -   High reliability (e.g. for vehicle safety applications, such as        self-driving cars)    -   Low device cost and energy consumption    -   Flexible spectrum usage    -   Flexible mobility

An example configuration of a wireless communications network which usessome of the terminology proposed for NR and 5G is shown in FIG. 2. InFIG. 2 a plurality of transmission and reception points (TRP) 210 areconnected to distributed control units (DU) 220, 230 by a connectioninterface represented as a line 203. Each of the transmitter receiverpoints (TRP) 210 is arranged to transmit and receive signals via awireless access interface within a radio frequency bandwidth availableto the wireless communications network. Thus within a range forperforming radio communications via the wireless access interface, eachof the TRP 210, forms a cell of the wireless communications network asrepresented by a dashed line 208. As such wireless communicationsdevices 104 which are within a radio communications range provided bythe cells 210 can transmit and receive signals to and from the TRP 210via the wireless access interface. Each of the distributed control units220, 230 are connected to a co-ordinating unit (CU) 214 via an interface216. The CU 214 is then connected to the a core network 217 which maycontain all other functions required for communicating data to and fromthe wireless communications devices and the core network 217 may beconnected to other networks 218.

The elements of the wireless access network shown in FIG. 2 may operatein a similar way to corresponding elements of an LTE network such asthat shown in FIG. 1. It will be appreciated that operational aspects ofthe telecommunications network represented in FIG. 2, and of othernetworks discussed herein in accordance with embodiments of thedisclosure, which are not specifically described (for example inrelation to specific communication protocols and physical channels forcommunicating between different elements) may be implemented inaccordance with any known techniques, for example according to currentlyused approaches for implementing such operational aspects of wirelesstelecommunications systems, e.g. in accordance with the relevantstandards.

The TRPs 210 of FIG. 2 may in part have a corresponding functionality toa base station or eNodeB 101 of an LTE network, and so the terms TRP andeNodeB in the following description are interchangeable. Base stations,which are an example of radio network infrastructure equipment, may alsobe referred to as transceiver stations/NodeBs/eNodeBs (eNBs)/gNodeBs(gNBs), and so forth. Similarly the communications devices 104 may havea functionality corresponding to devices know for operation with an LTEnetwork and may also be referred to as mobile stations, user equipment(UE), user terminal, terminal device, mobile radio, communicationsdevice, and so forth. It will be appreciated therefore that operationalaspects of a new RAT network (for example in relation to specificcommunication protocols and physical channels for communicating betweendifferent elements) may be different to those known from LTE or otherknown mobile telecommunications standards. However, it will also beappreciated that each of the core network component, base stations andterminal devices of a new RAT network will be functionally similar to,respectively, the core network component, base stations and terminaldevices of an LTE wireless communications network.

Coexistence Between NR and LTE

At least for initial deployment, NR and LTE are expected to coexist.Coexistence can be implemented using the same frequency resources but NRand LTE are differentiated using time division multiplexing (TDM). Forexample, NR may use LTE multicast-broadcast single frequency network(MBSFN) subframes, where there are up to a maximum of six LTE MBSFNsubframes in each radio frame, as shown in FIG. 3. As shown in FIG. 3,six LTE MBSFN subframes 302 (subframes 1, 2, 3, 6, 7, 8) are used for NRtransmissions, and the remaining subframes 304 are used for LTEtransmissions. Another implementation is to use separate frequencyresources and implement NR as a secondary carrier in a multi-carrieroperation. Here, LTE uses one frequency carrier 402 and NR uses anotherfrequency carrier 404 as shown in FIG. 4.

It will be appreciated that an MBSFN subframe consists of an LTE controlregion and a blank region. The LTE control region contains LTE controlchannels (e.g. physical downlink control channel (PDCCH), physicalhybrid-ARQ indicator channel (PHICH)) and cell-specific referencesignals (CRS). The blank region is not modulated. The reason for havingan LTE control channel region in the MBSFN subframe is to allow thegNodeB to signal to the UE the following:

-   -   PHICH provides ACK/NACK information related to previous uplink        transmissions from the UE.    -   PDCCH is used for indicating uplink allocations to the UE. The        gNodeB signals a PDCCH to the UE to assign a physical uplink        shared channel (PUSCH) in a future subframe. The PUSCH is        transmitted in a future subframe and is not impacted by MBSFN        transmissions (since PUSCH is an uplink transmission, not a        downlink transmission). Note that the UE monitors for “PDCCH        indicating uplink allocations” by performing blind decoding for        downlink control information (DCI) format 0 or DCI format 4.    -   PDCCH for indicating transmit power control commands to the UE.        Note that the UE monitors for these by blind decoding for DCI        formats 3 or 3A.

However, the LTE UE does not monitor for PDCCH indicating downlinkallocations to the UE in an MBSFN subframe. In LTE, there is a rule thatstates that the PDCCH allocating downlink resources to the UE insubframe ‘n’ relates to a PDSCH in subframe ‘n’. Since there is no PDSCHregion in MBSFN subframes, it is evident that there is no point in theUE monitoring PDCCH for downlink allocations in MBSFN subframes. Assuch, the UE does not need to blind decode for DCI formats 1->2C inMBSFN subframes.

When NR occupies an MBSFN subframe (as discussed above, for example withreference to the subframes 302 in FIG. 3), the NR transmission does notoccupy the LTE control channel region. FIG. 5 shows the structure of anMBSFN subframe used to transmit NR. The subframe consists of an LTEcontrol channel region 502 occupying OFDM symbols 0 and 1. The LTEcontrol channel region 502 also contains LTE CRS 504. The NR region ofthe subframe occupies OFDM symbols 2 to 13 (where the OFDM symbolduration is defined with reference to LTE), and comprises an NR controlchannel region 512 and an NR data region 514. The NR region canimplement a different numerology to the numerology of the LTE region. Itis evident that if an NR UE is to be scheduled in an MBSFN subframe,such as the one shown in FIG. 5, there is inefficiency in that the NRcontrol channel occupies NR resources, even though the LTE controlchannel may not be used to serve LTE UEs. As can be seen in FIG. 5, anLTE DCI 506 in the LTE control channel region (e.g. DCI format 0) mayallocate LTE PUSCH 508 in a future subframe and an NR DCI 516 in the NRcontrol channel region 512 allocating NR PDSCH 518 in the NR data region514 in the same subframe.

NR-LTE coexistence may serve UEs that are only capable of LTE or onlycapable of NR (i.e. LTE UEs occupy LTE portions of the resource, such assubframes 304 in FIG. 3 and NR UEs occupy NR portions of the resource,such as subframes 302 in FIG. 3). It is also expected that some UEs maybe both LTE and NR capable and hence some inter-working between NR andLTE would be beneficial for such UEs.

It is well understood that it is inefficient from a statisticalmultiplexing perspective to dedicate some fixed resource for one type ofUE and dedicate some other fixed resource for another type of UE.Consider for example, the frame structure of FIG. 3. If data arrives foran LTE UE in subframe 1, that data cannot be scheduled to the LTE UE,even if there are no NR UEs active in subframe 1; the UE can only bescheduled in subframe 4, at which time there may be other LTE UEs thatneed to be served.

In [4] it is proposed that LTE can be further evolved to allow higherdegree of adaptation/flexibility in time/frequency for enhanced NR-LTEinter-working. Embodiments of the present technique are related tomethods for NR-LTE inter-working. Embodiments of the present techniqueare related to the concept of a master RAT, or anchor carrier. Themaster RAT/anchor carrier is the base RAT technology that the celloperates on. Downlink control channel signaling is carried on the masterRAT. In FIG. 3, LTE is the master RAT and the NR system is inserted intothe LTE frame structure. However, as would be appreciated by thoseskilled in the art, embodiments of the present technique could equallyapply to either NR or LTE as the master RAT.

It was proposed in [5] that handover should be supported between LTEcells connected to the Evolved Packet Core (EPC) and LTE cells connectedto the 5G Core Network (5G-CN, or 5GC). FIG. 6 illustrates an exemplaryhandover procedure between a first (source) eNodeB 602 connected to a UE601 and a second (target) eNodeB 603 involving two core networks; the5GC 604 and EPC 605. In step 0, the UE 601 is connected to the sourceeNodeB 602, which controls an LTE cell, and to the 5GC 604. In step 1,the UE 601 sends a Radio Resource Control (RRC) measurement report tothe source eNodeB 602.

In step 2, the source eNodeB 602 must have sufficient information todecide if it needs to trigger an S1 or X2 handover, the S1 interfacebeing that between an eNodeB and a Core Network (CN), and the X2interface being that used to interconnect eNodeBs. If the target cellcontrolled by the target eNodeB 603 supports connection to 5GC 604, thenX2 handover can be triggered. However, in the case of FIG. 6, since achange of CN should take place, S1 handover should be triggered. Thesource eNodeB 602 must be aware of the target cell capability, and itsconnection to a CN.

Automatic Neighbour Relation (ANR) Function

It has been agreed that a cell connected to both 5GC and EPC willbroadcast Non-Access Stratum (NAS) parameters related to both CNs.Current automatic neighbour relation (ANR) framework is described below,whereby the UE reports parameters such as Cell Identity (CID), TrackingArea Code (TAC), Location Area Code (LAC), Public Land Mobile Network(PLMN) Identities, and Closed Subscriber Group (CSG) IDs. FIGS. 7, 8 and9 below, along with much of the associated wording (which has beenadapted herein), are taken from [6], and show neighbour cell management.

The purpose of the Automatic Neighbour Relation (ANR) function is torelieve the operator from the burden of manually managing NeighbourRelations (NRs). FIG. 7 shows ANR and its environment. The ANR function702 resides in the eNB 701 and manages the conceptual Neighbour RelationTable (NRT) 704. Located within ANR 702, the Neighbour DetectionFunction 706 finds new neighbours and adds them to the NRT 704. ANR 702also contains the Neighbour Removal Function 708 which removes outdatedNRs. The Neighbour Detection Function 706 and the Neighbour RemovalFunction 708 are implementation specific.

A Neighbour cell Relation (NR) in the context of ANR is defined asfollows. An existing Neighbour Relation from a source cell to a targetcell means that eNB controlling the source cell:

-   -   a) Knows the ECGI/CGI and PCI of the target cell.    -   b) Has an entry in the Neighbour Relation Table for the source        cell identifying the target cell.    -   c) Has the attributes in this Neighbour Relation Table entry        defined, either by O&M or set to default values.

For each cell that the eNB has, the eNB keeps a NRT, as shown in FIG. 7.For each NR, the NRT contains the Target Cell Identifier (TCI), whichidentifies the target cell. For E-UTRAN, the TCI corresponds to theE-UTAN Cell Global Identifier (ECGI) and Physical Cell Identifier (PCI)of the target cell. Furthermore, each NR has three attributes, theNoRemove, the NoHO and the NoX2 attribute. These attributes have thefollowing definitions:

-   -   No Remove: If checked, the eNB shall not remove the Neighbour        cell Relation from the NRT.    -   No HO: If checked, the Neighbour cell Relation shall not be used        by the eNB for handover reasons.    -   No X2: If checked, the Neighbour Relation shall not use an X2        interface in order to initiate procedures towards the eNB        parenting the target cell.

Neighbour cell Relations are cell-to-cell relations, and areunidirectional, while an X2 link is set up between two eNBs, and isbidirectional. The neighbour information exchange, which occurs duringthe X2 Setup procedure or in the eNB Configuration Update procedure, maybe used for ANR purposes. As shown in FIG. 7, the ANR function 702 alsoallows operation and maintenance (O&M) 710 to manage the NRT 704. O&M710 can add and delete NRs. It can also change the attributes of the NRT704. The O&M 710 system is informed about changes in the NRT 704.

The ANR (Automatic Neighbour Relation) function relies on cellsbroadcasting their identity on global level, E-UTRAN Cell GlobalIdentifier (ECGI). The function is illustrated in FIG. 8, and works asfollows:

The eNB serving cell A 801 has an ANR function. As a part of the normalcall procedure, the eNB instructs each UE to perform measurements onneighbour cells. The eNB may use different policies for instructing theUE to do measurements, and when to report them to the eNB.

-   -   1. The UE 804 sends a measurement report regarding cell B 802.        This report contains Cell B's PCI, but not its ECGI.    -   2. When the eNB 801 receives a UE 804 measurement report        containing the PCI, the following sequence may be used. The eNB        801 instructs the UE 804, using the newly discovered PCI as        parameter, to read the ECGI, the TAC and all available PLMN        ID(s) of the related neighbour cell 802. To do so, the eNB 801        may need to schedule appropriate idle periods to allow the UE        804 to read the ECGI from the broadcast channel of the detected        neighbour cell 802.    -   3. When the UE 804 has found out the new cell's ECGI, the UE 804        reports the detected ECGI to the serving cell eNB 801. In        addition the UE 804 reports the tracking area code and all PLMN        IDs that have been detected. If the detected cell 802 is a CSG        or hybrid cell, the UE 804 also reports the CSG ID to the        serving cell eNB 801.    -   4. The eNB 801 decides to add this neighbour relation, and can        use PCI and ECGI to:        -   a Lookup a transport layer address to the new eNB 802.        -   b Update the Neighbour Relation List.        -   c If needed, setup a new X2 interface towards this eNB 802.

The eNB may differentiate the open access HeNB from the other types of(H)eNB by the PCI configuration or ECGI configuration.

For Inter-RAT and Inter-Frequency ANR, each cell contains an InterFrequency Search list. This list contains all frequencies that shall besearched. For Inter-RAT cells, the NoX2 attribute in the NRT ispresently absent, as X2 is currently only defined for E-UTRAN. However,it is expected that the X2 interface could also be defined between anE-UTRAN (LTE) eNodeB and a NR (5G) eNodeB. The function is illustratedin FIG. 9, and works as follows:

The eNB serving cell A 901 has an ANR function. During connected mode,the eNB can instruct a UE to perform measurements and detect cells onother RATs/frequencies. The eNB may use different policies forinstructing the UE to do measurements, and when to report them to theeNB.

-   -   1 The eNB 901 instructs a UE 904 to look for neighbour cells in        the target RATs/frequencies. To do so the eNB 901 may need to        schedule appropriate idle periods to allow the UE 904 to scan        all cells in the target RATs/frequencies.    -   2 The UE 904 reports the PCI of the detected cells 902 in the        target RATs/frequencies. The PCI is defined by the carrier        frequency and the Primary Scrambling Code (PSC) in case of UTRAN        FDD cell, by the carrier frequency and the cell parameter ID in        case of UTRAN TDD cell, by the Band Indicator+BSIC+BCCH ARFCN in        case of GERAN cell and by the PN Offset in case of CDMA2000        cell.    -   3 When the eNB 901 receives UE 904 reports containing PCIs of        cell(s) the following sequence may be used. The eNB 901        instructs the UE 904, using the newly discovered PCI as        parameter, to read the CGI and the RAC of the detected neighbour        cell 902 in case of GERAN detected cells, CGI, LAC, RAC and all        broadcasted PLMN-ID(s) in case of UTRAN detected cells and CGI        in case of CDMA2000 detected cells. For the inter-frequency        case, the eNB 901 instructs the UE 904, using the newly        discovered PCI as parameter, to read the ECGI, TAC and all        available PLMN ID(s) of the inter-frequency detected cell 902.        The UE 904 ignores transmissions from the serving cell 901 while        finding the requested information transmitted in the broadcast        channel of the detected inter-system/inter-frequency neighbour        cell 902. To do so, the eNB 901 may need to schedule appropriate        idle periods to allow the UE 904 to read the requested        information from the broadcast channel of the detected        inter-RAT/inter-frequency neighbour cell 902.    -   4 After the UE 904 has read the requested information in the new        cell 902, it reports the detected CGI and RAC (in case of GERAN        detected cells) or CGI, LAC, RAC and all broadcasted PLMN-ID(s)        (in case of UTRAN detected cells) or CGI (in case of CDMA2000        detected cells) to the serving cell eNB 901. In the        inter-frequency case, the UE 904 reports the ECGI, the, tracking        area code and all PLMN-ID(s) that have been detected. If the        detected cell 902 is a CSG or hybrid cell, the UE 904 also        reports the CSG ID to the serving cell eNB 901.    -   5 The eNB 901 updates its inter-RAT/inter-frequency Neighbour        Relation Table. In the inter-frequency case and if needed, the        eNB 901 can use the PCI and ECGI for a new X2 interface setup        towards this eNB 902.

In step 3b as shown in FIG. 9, the UE 904 reads neighbouring cell systeminformation in order to acquire the information required to be reportedback to the serving cell 901. It is possible that only a few cells underthe control of an eNB are connected to 5GC or both core networks andother cells connect only to EPC. This should typically be the case fornetwork sharing whereby the new incumbent operator has 5GC and cellscontrolled by an eNB represent a mix of coverage (EPC+5GC) and capacity(either 5GC or EPC) or incumbent operator share cells on one frequencyonly and cells operating on that frequency connect to both 5GC and EPC.Other cells connect only to EPC.

Another case could be a combination of a macro and a small cell (RRH)whereby the RRH is connected to 5GC and EPC but the macro cell isconnected to EPC only. These are few examples highlighting the need formaintaining a new entry in the neighbour relationship table for CNconnectivity, such that a serving cell is able to make a decision as towhether an S1 or X2 based handover procedure should be triggered for aparticular UE. In addition, the serving cell may require suchinformation so as to determine whether an X2 interface needs to be setuptowards such a cell.

ANR Enhancement for LTE Cell Connected to 5GC/EPC

Embodiments of the present technique introduce an enhanced ANR mechanismfor an LTE cell which is connected to both the EPC and 5GC. In such anenhanced ANR mechanism, the UE reports, based on (for example) anindication broadcasted in the system information, if a neighboring cellhas a connection to the 5GC or both CNs. It is stated in [6] that thisinformation can be derived by the UE based on either simply presence of5GC NAS information in the system information or an explicit indicationcan be broadcasted in earlier SIBs (MIB, SIB1, and SIB2). Most likely,this would be broadcast in SIB1, as it has NAS information, and the UEgets other SON-ANR related information after reading SIB1.

A first embodiment of the present technique is described with relationto FIG. 10. FIG. 10 illustrates a method for use in a mobilecommunications network 1000 comprising a plurality of infrastructureequipment 1001, 1011 each providing wireless connectivity within atleast one cell, and a communications device 1021 configured tocommunicate wirelessly with at least a first of the infrastructureequipment 1001 in control of a first cell. The method comprisesdetermining 1030, at the communications device 1021, whether a secondcell under control of a second of the infrastructure equipment 1011 isconnected to a first core network operating in accordance with a firstcommunications protocol or both of the first core network and a secondcore network operating in accordance with a second communicationsprotocol, the second cell being a neighbour of the first cell, andtransmitting 1040, by the communications device 1021, an automaticneighbour relation report to the first infrastructure equipment 1001,the automatic neighbour relation report comprising an indication ofwhether the second cell is connected to the first core network or bothof the first core network and the second core network.

Each of the communications device 1021 and the infrastructure equipment1001, 1011 comprise a transmitter (or transmitter circuitry) 1022, 1002,1012, a receiver (or receiver circuitry) 1024, 1004, 1014, 1024, and acontroller (or controller circuitry 1026, 1006, 1016. Each of thecontrollers 1026, 1006, 1016 may be, for example, a microprocessor, aCPU, or a dedicated chipset, etc.

Alternatively or in addition, the X2 setup message may be modified. X2setup is sent with a new information element (IE) indicating support for5GC or both EPC and 5GC if the initiating node supports connection to5GC or both CNs. If the receiving eNodeB is a legacy (LTE only) eNodeBthen it won't understand the new IEs, and therefore won't send any newIEs about its own support of 5GC or both CNs. Otherwise, the receivingnode will in response send its support for 5GC or both CNs. In otherwords, in some arrangements of the first embodiment, the methodcomprises transmitting, by the first infrastructure equipment, aconnection setup request message, to the second infrastructureequipment, the connection setup request message comprising an indicationof whether the first cell is connected to the first core network or bothof the first core network and the second core network. Further, themethod may comprise receiving, at the second infrastructure equipment,the connection setup request message, transmitting, by the secondinfrastructure equipment, based on the connection setup request message,a connection response message comprising an indication of whether thesecond cell is connected to the first core network or both of the firstcore network and the second core network. If both of the first cell andthe second cell are connected to the first core network or both of thefirst core network and the second core network, the method may alsocomprise an interface between the first infrastructure equipment and thesecond infrastructure equipment.

In some arrangements of the first embodiment, the determination is madeby the communications device based on a bit broadcasted by the secondinfrastructure equipment, the bit indicating whether the second cell isconnected to the first core network or both of the first core networkand the second core network. Alternatively, the determination is made bythe communications device based on non-access stratum system informationreceived from the second infrastructure equipment.

A second embodiment of the present technique, in which the X2 setupmessage is modified as described above in absence of the ANRenhancement, provides a method for use in a mobile communicationsnetwork, the mobile communications network comprising a plurality ofinfrastructure equipment each providing wireless connectivity within atleast one cell, and a communications device configured to communicatewirelessly with at least a first of the infrastructure equipment incontrol of a first cell. The method comprises transmitting, by the firstinfrastructure equipment, a connection setup request message, to asecond of the infrastructure equipment in control of a second cell, theconnection setup request message comprising an indication of whether thefirst cell is connected to a first core network operating in accordancewith a first communications protocol or both of the first core networkand a second core network operating in accordance with a secondcommunications protocol, the second cell being a neighbour of the firstcell. In some arrangements of the second embodiment the method comprisesreceiving, at the second infrastructure equipment, the connection setuprequest message, transmitting, by the second infrastructure equipment,based on the connection setup request message, a connection responsemessage comprising an indication of whether the second cell is connectedto the first core network or both of the first core network and thesecond core network. If both of the first cell and the second cell areconnected to the first core network or both of the first core networkand the second core network, the method may also comprise forming aninterface between the first infrastructure equipment and the secondinfrastructure equipment.

It may be questionable if the X2 interface is needed between two nodeshaving 5GC to EPC or vice versa handover, as a change of core networkwill need to involve the core network. Only data forwarding can be donevia X2 in such cases and termination points can be shared via existingS1 messages and should already be possible. However, the X2 interface issetup for all the cells controlled by the eNodeB and as mentioned above,only a few cells may require knowledge about CN connectivity in thetarget cell, and the X2 interface may exist for other legacy cellsconnected to EPC only or 5GC only. The below table lays out the variousscenarios in terms of CN connectivity of source and target cells, andthe type of handover therefore which will be performed. In addition,Table I below defines whether a new ANR enhancement will be needed ineach of the scenarios.

TABLE I Source cell Target cell New ANR enhancement connectivityconnectivity Type of handover needed? EPC EPC X2 if present No EPC 5GCS1 as change of CN is Yes, to distinguish from the case required aboveEPC 5GC + EPC X2 if present No, handover will be EPC-EPC first 5GC EPCS1 Yes, inter CN handover. If SON- ANR report is not enhanced forreporting connection to EPC then it implies connection to EPC. 5GC 5GCX2 Yes, if absence of enhanced reporting implies connection to EPC thenwe need explicit signaling to identify connection to 5GC EPC + 5GC 5GCS1 or X2 depending on Yes, if absence of enhanced source side UEreporting implies connection to connection EPC then we need explicitsignaling to identify connection to 5GC EPC + 5GC EPC + 5GC S1 or X2depending on Yes, if absence of enhanced source side UE reportingimplies connection to connection EPC then we need explicit signaling toidentify connection to 5GC

Embodiments of the present technique may therefore provide ways in whichsource cells may determine whether target cells for handover supportconnection to the NR core network. Specifically to the first embodimentof the present technique, the ANR mechanism is enhanced to supportreporting of a target cell connectivity to 5GC or both CNs.

The following numbered paragraphs provide further example aspects andfeatures of the present technique:

Paragraph 1. A method for use in a mobile communications network, themobile communications network comprising

-   -   a plurality of infrastructure equipment each providing wireless        connectivity within at least one cell, and    -   a communications device configured to communicate wirelessly        with at least a first of the infrastructure equipment in control        of a first cell, wherein the method comprises    -   determining, at the communications device, whether a second cell        under control of a second of the infrastructure equipment is        connected to a first core network operating in accordance with a        first communications protocol or both of the first core network        and a second core network operating in accordance with a second        communications protocol, the second cell being a neighbour of        the first cell, and    -   transmitting, by the communications device, an automatic        neighbour relation report to the first infrastructure equipment,        the automatic neighbour relation report comprising an indication        of whether the second cell is connected to the first core        network or both of the first core network and the second core        network.

Paragraph 2. A method according to Paragraph 1, wherein the methodcomprises

-   -   transmitting, by the first infrastructure equipment, a        connection setup request message, to the second infrastructure        equipment, the connection setup request message comprising an        indication of whether the first cell is connected to the first        core network or both of the first core network and the second        core network.

Paragraph 3. A method according to Paragraph 2, wherein the methodcomprises

-   -   receiving, at the second infrastructure equipment, the        connection setup request message, and    -   transmitting, by the second infrastructure equipment, based on        the connection setup request message, a connection response        message comprising an indication of whether the second cell is        connected to the first core network or both of the first core        network and the second core network.

Paragraph 4. A method according to Paragraph 3, wherein the methodcomprises, if both of the first cell and the second cell are connectedto the first core network or both of the first core network and thesecond core network,

-   -   forming an interface between the first infrastructure equipment        and the second infrastructure equipment.

Paragraph 5. A method according to any of Paragraphs 1 to 4, wherein thedetermination is made by the communications device based on a bitbroadcasted by the second infrastructure equipment, the bit indicatingwhether the second cell is connected to the first core network or bothof the first core network and the second core network.

Paragraph 6. A method according to any of Paragraphs 1 to 4, wherein thedetermination is made by the communications device based on non-accessstratum system information received from the second infrastructureequipment.

Paragraph 7. A mobile communications network comprising

-   -   a plurality of infrastructure equipment each providing wireless        connectivity within at least one cell, and    -   a communications device configured to communicate wirelessly        with at least a first of the infrastructure equipment in control        of a first cell, wherein the communications device is configured    -   to determine whether a second cell under control of a second of        the infrastructure equipment is connected to a first core        network of a first communications protocol or both of the first        core network and a second core network of a second        communications protocol, the second cell being a neighbour of        the first cell, and    -   to transmit an automatic neighbour relation report to the first        infrastructure equipment, the automatic neighbour relation        report comprising an indication of whether the second cell is        connected to the first core network or both of the first core        network and the second core network.

Paragraph 8. Circuitry for a mobile communications network comprising

-   -   a plurality of infrastructure equipment each providing wireless        connectivity within at least one cell, and    -   a communications device configured to communicate wirelessly        with at least a first of the infrastructure equipment in control        of a first cell, wherein the communications device is configured    -   to determine whether a second cell under control of a second of        the infrastructure equipment is connected to a first core        network operating in accordance with a first communications        protocol or both of the first core network and a second core        network operating in accordance with a second communications        protocol, the second cell being a neighbour of the first cell,        and    -   to transmit an automatic neighbour relation report to the first        infrastructure equipment, the automatic neighbour relation        report comprising an indication of whether the second cell is        connected to the first core network or both of the first core        network and the second core network.

Paragraph 9. A communications device for use in a mobile communicationsnetwork, the mobile communications network comprising a plurality ofinfrastructure equipment each providing wireless connectivity within atleast one cell, wherein the communications device comprises

-   -   transmitter circuitry configured to transmit signals to the        infrastructure equipment,    -   receiver circuitry configured to receive signals from the        infrastructure equipment, and    -   controller circuitry configured to control the transmitter        circuitry and the receiver circuitry    -   to communicate wirelessly with at least a first of the        infrastructure equipment in control of a first cell,    -   to determine whether a second cell under control of a second of        the infrastructure equipment is connected to a first core        network operating in accordance with a first communications        protocol or both of the first core network and a second core        network operating in accordance with a second communications        protocol, the second cell being a neighbour of the first cell,        and        -   to transmit an automatic neighbour relation report to the            first infrastructure equipment, the automatic neighbour            relation report comprising an indication of whether the            second cell is connected to the first core network or both            of the first core network and the second core network.

Paragraph 10. A method of operating a communications device for use in amobile communications network, the mobile communications networkcomprising a plurality of infrastructure equipment each providingwireless connectivity within at least one cell, wherein the methodcomprises

-   -   communicating wirelessly with at least a first of the        infrastructure equipment in control of a first cell,    -   determining whether a second cell under control of a second of        the infrastructure equipment is connected to a first core        network operating in accordance with a first communications        protocol or both of the first core network and a second core        network operating in accordance with a second communications        protocol, the second cell being a neighbour of the first cell,        and    -   transmitting an automatic neighbour relation report to the first        infrastructure equipment, the automatic neighbour relation        report comprising an indication of whether the second cell is        connected to the first core network or both of the first core        network and the second core network.

Paragraph 11. Circuitry for a communications device for use in a mobilecommunications network, the mobile communications network comprising aplurality of infrastructure equipment each providing wirelessconnectivity within at least one cell, wherein the communications devicecomprises

-   -   transmitter circuitry configured to transmit signals to the        infrastructure equipment,    -   receiver circuitry configured to receive signals from the        infrastructure equipment, and    -   controller circuitry configured to control the transmitter        circuitry and the receiver circuitry    -   to communicate wirelessly with at least a first of the        infrastructure equipment in control of a first cell,    -   to determine whether a second cell under control of a second of        the infrastructure equipment is connected to a first core        network operating in accordance with a first communications        protocol or both of the first core network and a second core        network operating in accordance with a second communications        protocol, the second cell being a neighbour of the first cell,        and    -   to transmit an automatic neighbour relation report to the first        infrastructure equipment, the automatic neighbour relation        report comprising an indication of whether the second cell is        connected to the first core network or both of the first core        network and the second core network.

Paragraph 12. An infrastructure equipment for use in a mobilecommunications network, the mobile communications network comprising oneor more other infrastructure equipment, the infrastructure equipment andone or more other infrastructure equipment each providing wirelessconnectivity within at least one cell, and a communications deviceconfigured to communicate wirelessly with at least the infrastructureequipment, wherein the infrastructure equipment is in control of a firstcell and comprises

-   -   transmitter circuitry configured to transmit signals to the        communications device and the other infrastructure equipment,    -   receiver circuitry configured to receive signals from the        communications device and the other infrastructure equipment,        and    -   controller circuitry configured to control the transmitter        circuitry and the receiver circuitry    -   to receive an automatic neighbour relation report from the        communications device, the automatic neighbour relation report        comprising an indication of whether a second cell under control        of one of the other infrastructure equipment is connected to a        first core network operating in accordance with a first        communications protocol or both of the first core network and a        second core network operating in accordance with a second        communications protocol, the second cell being a neighbour of        the first cell.

Paragraph 13. A method of operating an infrastructure equipment for usein a mobile communications network, the mobile communications networkcomprising one or more other infrastructure equipment, theinfrastructure equipment and other infrastructure equipment eachproviding wireless connectivity within at least one cell, and acommunications device configured to communicate wirelessly with at leastthe infrastructure equipment, wherein the infrastructure equipment is incontrol of a first cell, the method comprising

-   -   receiving an automatic neighbour relation report from the        communications device, the automatic neighbour relation report        comprising an indication of whether a second cell under control        of one of the other infrastructure equipment is connected to a        first core network operating in accordance with a first        communications protocol or both of the first core network and a        second core network operating in accordance with a second        communications protocol, the second cell being a neighbour of        the first cell.

Paragraph 14. Circuitry for an infrastructure equipment for use in amobile communications network, the mobile communications networkcomprising one or more other infrastructure equipment, theinfrastructure equipment and one or more other infrastructure equipmenteach providing wireless connectivity within at least one cell, and acommunications device configured to communicate wirelessly with at leastthe infrastructure equipment, wherein the infrastructure equipment is incontrol of a first cell and comprises

-   -   transmitter circuitry configured to transmit signals to the        communications device and the other infrastructure equipment,    -   receiver circuitry configured to receive signals from the        communications device and the other infrastructure equipment,        and    -   controller circuitry configured to control the transmitter        circuitry and the receiver circuitry    -   to receive an automatic neighbour relation report from the        communications device, the automatic neighbour relation report        comprising an indication of whether a second cell under control        of one of the other infrastructure equipment is connected to a        first core network operating in accordance with a first        communications protocol or both of the first core network and a        second core network operating in accordance with a second        communications protocol, the second cell being a neighbour of        the first cell.

Paragraph 15. A method for use in a mobile communications network, themobile communications network comprising

-   -   a plurality of infrastructure equipment each providing wireless        connectivity within at least one cell, and    -   a communications device configured to communicate wirelessly        with at least a first of the infrastructure equipment in control        of a first cell, wherein the method comprises    -   transmitting, by the first infrastructure equipment, a        connection setup request message, to a second of the        infrastructure equipment in control of a second cell, the        connection setup request message comprising an indication of        whether the first cell is connected to a first core network        operating in accordance with a first communications protocol or        both of the first core network and a second core network        operating in accordance with a second communications protocol,        the second cell being a neighbour of the first cell.

Paragraph 16. A method according to Paragraph 15, wherein the methodcomprises

-   -   receiving, at the second infrastructure equipment, the        connection setup request message,    -   transmitting, by the second infrastructure equipment, based on        the connection setup request message, a connection response        message comprising an indication of whether the second cell is        connected to the first core network or both of the first core        network and the second core network.

Paragraph 17. A method according to Paragraph 16, wherein the methodcomprises, if both of the first cell and the second cell are connectedto the first core network or both of the first core network and thesecond core network,

-   -   forming an interface between the first infrastructure equipment        and the second infrastructure equipment.

Paragraph 18. A mobile communications network comprising

-   -   a plurality of infrastructure equipment each providing wireless        connectivity within at least one cell, and    -   a communications device configured to communicate wirelessly        with at least a first of the infrastructure equipment in control        of a first cell, wherein the first infrastructure equipment is        configured    -   to transmit a connection setup request message to a second of        the infrastructure equipment in control of a second cell, the        connection setup request message comprising an indication of        whether the first cell is connected to a first core network        operating in accordance with a first communications protocol or        both of the first core network and a second core network        operating in accordance with a second communications protocol,        the second cell being a neighbour of the first cell.

Paragraph 19. Circuitry for a mobile communications network comprising

-   -   a plurality of infrastructure equipment each providing wireless        connectivity within at least one cell, and    -   a communications device configured to communicate wirelessly        with at least a first of the infrastructure equipment in control        of a first cell, wherein the first infrastructure equipment is        configured    -   to transmit a connection setup request message to a second of        the infrastructure equipment in control of a second cell, the        connection setup request message comprising an indication of        whether the first cell is connected to a first core network        operating in accordance with a first communications protocol or        both of the first core network and a second core network        operating in accordance with a second communications protocol,        the second cell being a neighbour of the first cell.

Paragraph 20. An infrastructure equipment for use in a mobilecommunications network, the mobile communications network comprising oneor more other infrastructure equipment, the infrastructure equipment andother infrastructure equipment each providing wireless connectivitywithin at least one cell, wherein the infrastructure equipment is incontrol of a first cell and comprises

-   -   transmitter circuitry configured to transmit signals to the        other infrastructure equipment,    -   receiver circuitry configured to receive signals from the other        infrastructure equipment, and    -   controller circuitry configured to control the transmitter        circuitry and the receiver circuitry    -   to transmit a connection setup request message to one of the        other infrastructure equipment in control of a second cell, the        connection setup request message comprising an indication of        whether the first cell is connected to a first core network        operating in accordance with a first communications protocol or        both of the first core network and a second core network        operating in accordance with a second communications protocol,        the second cell being a neighbour of the first cell.

Paragraph 21. A method of operating an infrastructure equipment for usein a mobile communications network, the mobile communications networkcomprising one or more other infrastructure equipment, theinfrastructure equipment and other infrastructure equipment eachproviding wireless connectivity within at least one cell, wherein theinfrastructure equipment is in control of a first cell, the methodcomprising

-   -   transmitting a connection setup request message to one of the        other infrastructure equipment in control of a second cell, the        connection setup request message comprising an indication of        whether the first cell is connected to a first core network        operating in accordance with a first communications protocol or        both of the first core network and a second core network        operating in accordance with a second communications protocol,        the second cell being a neighbour of the first cell.

Paragraph 22. Circuitry for an infrastructure equipment for use in amobile communications network, the mobile communications networkcomprising one or more other infrastructure equipment, theinfrastructure equipment and other infrastructure equipment eachproviding wireless connectivity within at least one cell, wherein theinfrastructure equipment is in control of a first cell and comprises

-   -   transmitter circuitry configured to transmit signals to the        other infrastructure equipment,    -   receiver circuitry configured to receive signals from the other        infrastructure equipment, and    -   controller circuitry configured to control the transmitter        circuitry and the receiver circuitry to transmit a connection        setup request message to one of the other infrastructure        equipment in control of a second cell, the connection setup        request message comprising an indication of whether the first        cell is connected to a first core network operating in        accordance with a first communications protocol or both of the        first core network and a second core network operating in        accordance with a second communications protocol, the second        cell being a neighbour of the first cell.

Numerous modifications and variations of the present disclosure arepossible in light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the disclosuremay be practiced otherwise than as specifically described herein.

In so far as embodiments of the disclosure have been described as beingimplemented, at least in part, by software-controlled data processingapparatus, it will be appreciated that a non-transitory machine-readablemedium carrying such software, such as an optical disk, a magnetic disk,semiconductor memory or the like, is also considered to represent anembodiment of the present disclosure.

It will be appreciated that the above description for clarity hasdescribed embodiments with reference to different functional units,circuitry and/or processors. However, it will be apparent that anysuitable distribution of functionality between different functionalunits, circuitry and/or processors may be used without detracting fromthe embodiments.

Described embodiments may be implemented in any suitable form includinghardware, software, firmware or any combination of these. Describedembodiments may optionally be implemented at least partly as computersoftware running on one or more data processors and/or digital signalprocessors. The elements and components of any embodiment may bephysically, functionally and logically implemented in any suitable way.Indeed the functionality may be implemented in a single unit, in aplurality of units or as part of other functional units. As such, thedisclosed embodiments may be implemented in a single unit or may bephysically and functionally distributed between different units,circuitry and/or processors.

Although the present disclosure has been described in connection withsome embodiments, it is not intended to be limited to the specific formset forth herein. Additionally, although a feature may appear to bedescribed in connection with particular embodiments, one skilled in theart would recognize that various features of the described embodimentsmay be combined in any manner suitable to implement the technique.

REFERENCES

-   [1] LTE for UMTS: OFDMA and SC-FDMA Based Radio Access, Harris Holma    and Antti Toskala, Wiley 2009, ISBN 978-0-470-99401-6.-   [2] RP-151621, “New Work Item: NarrowBand IOT NB-IOT,” Qualcomm, RAN    #69.-   [3] RP-160671, “New SID Proposal: Study on New Radio Access    Technology,” NTT DOCOMO, RAN #71.-   [4] R1-1611681, “Coexistence between NR and LTE,” Huawei, HiSilicon,    RAN1#87.-   [5] RP-170840, “New Work item on LTE connectivity to 5G-CN,” Huawei,    Ericsson, RAN #75.-   [6] 3GPP Specification 36.300, “Evolved Universal Terrestrial Radio    Access (E-UTRA) and Evolved Universal Terrestrial Radio Access    Network (E-UTRAN); Overall description; Stage 2,” 3^(rd) Generation    Partnership Project.

1. A method for use in a mobile communications network, the mobilecommunications network comprising a plurality of infrastructureequipment each providing wireless connectivity within at least one cell,and a communications device configured to communicate wirelessly with atleast a first of the infrastructure equipment in control of a firstcell, wherein the method comprises determining, at the communicationsdevice, whether a second cell under control of a second of theinfrastructure equipment is connected to a first core network operatingin accordance with a first communications protocol or both of the firstcore network and a second core network operating in accordance with asecond communications protocol, the second cell being a neighbour of thefirst cell, and transmitting, by the communications device, an automaticneighbour relation report to the first infrastructure equipment, theautomatic neighbour relation report comprising an indication of whetherthe second cell is connected to the first core network or both of thefirst core network and the second core network.
 2. A method according toclaim 1, wherein the method comprises transmitting, by the firstinfrastructure equipment, a connection setup request message, to thesecond infrastructure equipment, the connection setup request messagecomprising an indication of whether the first cell is connected to thefirst core network or both of the first core network and the second corenetwork.
 3. A method according to claim 2, wherein the method comprisesreceiving, at the second infrastructure equipment, the connection setuprequest message, and transmitting, by the second infrastructureequipment, based on the connection setup request message, a connectionresponse message comprising an indication of whether the second cell isconnected to the first core network or both of the first core networkand the second core network.
 4. A method according to claim 3, whereinthe method comprises, if both of the first cell and the second cell areconnected to the first core network or both of the first core networkand the second core network, forming an interface between the firstinfrastructure equipment and the second infrastructure equipment.
 5. Amethod according to claim 1, wherein the determination is made by thecommunications device based on a bit broadcasted by the secondinfrastructure equipment, the bit indicating whether the second cell isconnected to the first core network or both of the first core networkand the second core network.
 6. A method according to claim 1, whereinthe determination is made by the communications device based onnon-access stratum system information received from the secondinfrastructure equipment. 7.-8. (canceled)
 9. A communications devicefor use in a mobile communications network, the mobile communicationsnetwork comprising a plurality of infrastructure equipment eachproviding wireless connectivity within at least one cell, wherein thecommunications device comprises transmitter circuitry configured totransmit signals to the infrastructure equipment, receiver circuitryconfigured to receive signals from the infrastructure equipment, andcontroller circuitry configured to control the transmitter circuitry andthe receiver circuitry to communicate wirelessly with at least a firstof the infrastructure equipment in control of a first cell, to determinewhether a second cell under control of a second of the infrastructureequipment is connected to a first core network operating in accordancewith a first communications protocol or both of the first core networkand a second core network operating in accordance with a secondcommunications protocol, the second cell being a neighbour of the firstcell, and to transmit an automatic neighbour relation report to thefirst infrastructure equipment, the automatic neighbour relation reportcomprising an indication of whether the second cell is connected to thefirst core network or both of the first core network and the second corenetwork. 10.-11. (canceled)
 12. An infrastructure equipment for use in amobile communications network, the mobile communications networkcomprising one or more other infrastructure equipment, theinfrastructure equipment and one or more other infrastructure equipmenteach providing wireless connectivity within at least one cell, and acommunications device configured to communicate wirelessly with at leastthe infrastructure equipment, wherein the infrastructure equipment is incontrol of a first cell and comprises transmitter circuitry configuredto transmit signals to the communications device and the otherinfrastructure equipment, receiver circuitry configured to receivesignals from the communications device and the other infrastructureequipment, and controller circuitry configured to control thetransmitter circuitry and the receiver circuitry to receive an automaticneighbour relation report from the communications device, the automaticneighbour relation report comprising an indication of whether a secondcell under control of one of the other infrastructure equipment isconnected to a first core network operating in accordance with a firstcommunications protocol or both of the first core network and a secondcore network operating in accordance with a second communicationsprotocol, the second cell being a neighbour of the first cell. 13.-19.(canceled)
 20. An infrastructure equipment for use in a mobilecommunications network, the mobile communications network comprising oneor more other infrastructure equipment, the infrastructure equipment andother infrastructure equipment each providing wireless connectivitywithin at least one cell, wherein the infrastructure equipment is incontrol of a first cell and comprises transmitter circuitry configuredto transmit signals to the other infrastructure equipment, receivercircuitry configured to receive signals from the other infrastructureequipment, and controller circuitry configured to control thetransmitter circuitry and the receiver circuitry to transmit aconnection setup request message to one of the other infrastructureequipment in control of a second cell, the connection setup requestmessage comprising an indication of whether the first cell is connectedto a first core network operating in accordance with a firstcommunications protocol or both of the first core network and a secondcore network operating in accordance with a second communicationsprotocol, the second cell being a neighbour of the first cell. 21.-22.(canceled)